/**
 * Copyright 2023 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import {useState, useEffect, RefObject} from 'react'

const useSticky = (
  ref: RefObject<HTMLElement>,
  observerSettings = {threshold: [1]}
) => {
  const [isSticky, setIsSticky] = useState(false)

  useEffect(() => {
    if (!ref.current) return

    const observer = new IntersectionObserver(([e]) => {
      setIsSticky(e.intersectionRatio < 1)
    }, observerSettings)

    observer.observe(ref.current)

    return () => {
      if (!ref.current) return

      observer.unobserve(ref.current)
    }
  }, [])

  return {isSticky}
}

export default useSticky
